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A191128 Increasing sequence generated by these rules: a(1)=1, and if x is in a then 3x and 4x-1 are in a.

%I A191128 #8 Jul 13 2013 12:04:10
%S A191128 1,3,9,11,27,33,35,43,81,99,105,107,129,131,139,171,243,297,315,321,
%T A191128 323,387,393,395,417,419,427,513,515,523,555,683,729,891,945,963,969,
%U A191128 971,1161,1179,1185,1187,1251,1257,1259,1281,1283,1291,1539,1545,1547,1569,1571,1579,1665,1667,1675,1707,2049,2051,2059,2091,2187
%N A191128 Increasing sequence generated by these rules:  a(1)=1, and if x is in a then 3x and 4x-1 are in a.
%C A191128 See A191113.
%H A191128 Reinhard Zumkeller, <a href="/A191128/b191128.txt">Table of n, a(n) for n = 1..10000</a>
%t A191128 h = 3; i = 0; j = 4; k = -1; f = 1; g = 9;
%t A191128 a = Union[Flatten[NestList[{h # + i, j # + k} &, f, g]]]  (* A191128 *)
%t A191128 b = a/3; c = (a + 1)/4; r = Range[1, 1500];
%t A191128 d = Intersection[b, r] (* A191180 *)
%t A191128 e = Intersection[c, r] (* A191181 *)
%t A191128 m = (a + 1)/2  (* divisibility property *)
%o A191128 (Haskell)
%o A191128 import Data.Set (singleton, deleteFindMin, insert)
%o A191128 a191128 n = a191128_list !! (n-1)
%o A191128 a191128_list = f $ singleton 1
%o A191128    where f s = m : (f $ insert (3*m) $ insert (4*m-1) s')
%o A191128              where (m, s') = deleteFindMin s
%o A191128 -- _Reinhard Zumkeller_, Jun 01 2011
%Y A191128 Cf. A191113, A191180, A191181.
%K A191128 nonn
%O A191128 1,2
%A A191128 _Clark Kimberling_, May 27 2011